The concept of Brook as a skeleton musician, had already been thought up by Oda the first time he drew Laboon. Brook's overall design, however, was not finalized back then but the basic idea was kept for a long time until Brook was finally revealed.
In the anime, when Brook first joined the Straw Hats for dinner, the dinner that was being served was a banquet of varied octopus-based cuisine, among which were Takoyaki balls made by Sanji.
While this scene does not differ from the manga much due to the dinner's food not being specified in the latter, it does provide a possible contradiction to what is stated in the manga in a later scene. Namely, when Brook and the rest of the Straw Hats enjoy some Takoyaki as a reward for saving Hatchan, Brook states that it was the first time he enjoyed Takoyaki. However, it is only a possible contradiction, as Brook is not seen partaking of Sanji's Takoyaki.
The flashback of the first duel between Brook and Ryuma is handled differently in the manga and anime versions:
Originally in the manga, the duel against Ryuma is so fierce that pieces of Brook's bones are broken and fly off in the process as he takes hits from the zombie. While the duel is much longer with more moves portrayed in the anime, it is noticeably less violent by the fact that though Brook is attacked by Ryuma, there is only one instance where a few pieces of bone are broken off by the attacks.
The duel ultimately ends violently with Ryuma stabbing his sword through Brook's skull and creating a huge crack which fortunately "healed" over time. The duel in the anime ends considerably much different with Ryuma threatening to stab Brook's skull instead of stabbing through it like in manga.
While the anime portrayed the fight in the flashback less violently, it however portrayed the rematch between the two with the same intensity as in the manga. It showed scenes wherein Brook was stabbed by Ryuma with normally fatal but otherwise bone cracking strikes.
When informing Luffy's group on what transpired on the Thousand Sunny as it docked near Punk Hazard, his Jolly Roger on his tea cup is different. Neither are identical to his pre-timeskip personalized Jolly Roger, with the manga depicting his cane twice and is missing his top hat, while the anime shows the classic crossbones.
In the 4Kids English dub adaption of the anime, the sequence in which the Straw Hats encountered Laboon was cut for various reasons. Due to this, aside from parts of the story being changed in order to coincide with the cut, a plot hole was created in the 4Kids version of the anime concerning an integral part of Brook's character, namely Brook's relationship with the whale. Though the 4Kids dub stopped at the start of the Jaya Arc, the plot hole created still stands.
Like other members of the Straw Hat crew, Brook has his own personal jolly roger: it is a skull without a jaw with Brook's trademark afro, a top hat, and a cane in place of the cross bone mark. His jolly roger is also shown on his travel mug and tea cup. His jolly roger was seen worn by one of fans.
Oda has also revealed a post-timeskip jolly roger. The design for this one includes a full skull and an afro, with his new glasses and hat. His afro and skull is encircled by bones with his single guitar as his cross-bones in the background.
During the beginning of the Punk Hazard Arc Brook is seen drinking from a tea cup with a slightly different personalized jolly roger. The anime adaptation shown yet another version.
In Strong World, Brook was seen smoking. However, this is a non-canon source and he was never seen smoking in the canon series.
Brook is the oldest member of the Straw Hats, being 38 (dying 2 years after leaving Laboon, then spending a year seeking his body) at the time of his death and 88 years old when he meets the crew (most likely a reference to the number of keys on a piano).
Brook is one of two Straw Hats that was a captain of his pirate crew, the other being Jinbe.
Brook's height before the timeskip, 8'8" could be related to the usual number of keys on a piano, 88.
Before Brook fulfilled the position of musician, there was a running gag of the need for the position to be filled that was always being brought up by Luffy during important meetings with his crew on who should join next. Whenever the Straw Hats hold a serious meeting about a situation they are in that might require the addition of a new crew member with skills to aid in that situation, or anything similar like that, Luffy would always bring up the need of getting a musician. His reasoning is that pirates love to sing and a musician is essential to a pirate crew. Luffy's request however would always be turned down by his crew for more practical solutions to the situation.
Since the introduction of Brook's bounty, there was speculation of whether his 33,000,000 bounty was active or not. In Chapter 600, Marines declared that his bounty was still active, thus ending the speculation.
At the end of the Dressrosa Arc, his bounty gets an increase with an updated picture which shows he is recognized as a member of the Straw Hats.
Brook is the only Straw Hat to have never ridden aboard the Going Merry.
Brook is the only known person to have a wanted poster that is not formatted in the uniform style, instead the World Government used one of his old concert posters, and added the standard "WANTED" and "Dead or Alive", and replaced the "World Tour" with his bounty and the paragraph at the bottom.
In Episode 509, when Brook starts playing the composition to raise the people's spirits, the music played on his violin is the same piece played by Butler, "The song of the horn eaters", from the third movie. The music, however, was originally used to make animals start rampaging, rather than raise people's spirits.
Brook's model sheets in TOEI are named "Blook".
In One Piece Blue Deep: Characters World, Brook's post-timeskip height is said to be 277cm, 11cm taller than his pre-timeskip height. This appears to contradict what he said during his fight with Ryuma; that it was important for him to protect his afro because his body had stopped growing.
The idea of a skeleton musician was first conceived by Oda in the year 2000. 
↑ 2.02.1One Piece Manga and Anime — Vol.
50 Chapter 489 (p. 11) and Episode 381,
Brook reveals that he was the leader of the battle convoy of a certain kingdom before joining the Rumbar Pirates, and then his bounty as a pirate.
↑ 7.07.17.2SBSOne Piece Manga — Vol. 69 (p. 66),
First fan question: Oda-sensei, I have a question. Please tell me the current profiles (birthday, height, age) of all of the members of the Straw Hat Pirates! Second Fan question: Oda-sensei! Please tell me the order in which the members of the Straw Hat Pirates joined the crew! I'm really grateful!
↑ 8.08.1SBSOne Piece Manga — Vol. 50 (p. 86),
Fan question: Hello, Oda-sensei! I've been thinking about Brook's birthday! Since he has the Yomi Yomi Fruit, why not use yo-mi (4-3) to make April 3rd his birthday?!
↑SBSOne Piece Manga — Vol. 86 (p. 98),
Fan question: On page 28 in chapter 850 in volume 85, there's the bento that Sanji made. When you compare to the SBS on page 188 in volume 35, you can see that it exactly matches what was the crews' favorite meals, but I can't figure out the food on the left of the sandwich. Is it Brook's favorite food, which wasn't written in volume 45's SBS?
↑SBSOne Piece Manga — Vol. 73 (p. 144),
Fan question: I was looking up trivia on the Straw Hat Pirates, and I found that although they have all been given a favorite food, I cannot find anything about their least favorite. So what are each of the Straw Hat Pirates' least favorite foods?
↑SBSOne Piece Manga — Vol. 84 (p. 150),
Fan question: Oda Sensei!! Please tell me who from the Straw Hat Pirates likes ice cream, and who don't?
↑SBSOne Piece Manga — Vol. 79 (p. 142),
Fan question: In the Straw Hat Pirates, Sanji is obviously the one who is the best at cooking, but who else is good at cooking? What is everyone's speciality dish?
↑ 26.026.126.226.326.426.5SBSOne Piece Manga — Vol. 50 (p. 86),
Fan question: Congratulations on bringing Brook into the crew, Oda-sensei! I am all jelly-legged at the thought of him... like I am boneless! So now that the crew has reached eight other members, I was hoping you could answer all the personal questions you did earlier, for all of the folks who were not around at the time!
↑SBSOne Piece Manga — Vol. 59 (p. 186),
Fan question: Odacchi! I noticed an amazing thing!!! It is that if you show the Straw Hat Devil Fruit users in numbers, it will be the numbers from 1~10!!
Luffy→Gomu Gomu (220.127.116.11.), Chopper→Hito Hito (18.104.22.168), Robin→Hana Hana (22.214.171.124.), Brook→Yomi Yomi (126.96.36.199.)
(188.8.131.52.184.108.40.206), but there is no (2.9), so is the one who ate the Nikyu Nikyu (220.127.116.11.) no Mi, Bartholomew Kuma, gonna be a Straw Hat next? Please tell me!!!
↑SBSOne Piece Manga — Vol. 56 (p. 144),
Fan question: Nice to meet you, Oda-sensei. I have a question. If One Piece was set in the real world, which countries would the nine Straw Hat Pirates come from?
↑SBSOne Piece Manga — Vol. 59 (p. 96),
Fan question: Hello Oda Sensei~! Out of the blue but can you write what is inside Luffy's head? oh and your head too--. my friend's head is half pervert and half games.
↑SBSOne Piece Manga — Vol. 60 (p. 206),
Fan question: A question to the Hana Hana no Mi user, flower loving Robin <3. Which flower would suit each of the Straw Hat Pirates? Sister Robin can go with a flower she likes <3 by I like cosmoses.
↑SBSOne Piece Manga — Vol. 66 (p. 162),
Fan question: Hello Oda-sensei! In volume 62 when Sanji meets the mermaids and blows a shower of nosebleed, Chopper was saying his blood type was "S", but that sounds really different! What are the other blood types? If it is okay with you, I would like to know the blood types of all the Straw Hat Pirates!
↑SBSOne Piece Manga — Vol. 67 (p. 182),
Fan question: In chapter 654, Chopper turns down Nami's invitation to join her in the bath, saying "I wiped myself down the day before yesterday", right? Is it because he is a boy? Or a fruit user? Or maybe... because he is an animal? I am also interested in the bathing information for the rest of the Straw Hat Pirates.
↑ 33.033.1SBSOne Piece Manga — Vol. 72 (p. 46),
First fan question: It seems that Trafalgar Law, in the midst of his alliance with the Straw Hats, gives them some nicknames. What are all the things he calls the various members of the crew like Zoro and Franky? Second fan question: If the Straw Hat Pirates were different prefectures of Japan, what they would be? For example, would Nami be from Ehime, I would love to hear from you!
↑SBSOne Piece Manga — Vol. 74 (p. 126),
Fan question: I would like to know the Straw Hat Pirates' bed times and wake up times!
↑SBSOne Piece Manga — Vol. 76 (p. 42),
fan question: If the Straw Hat Pirates never became pirates, what would their careers of choice be?
↑SBSOne Piece Manga — Vol. 85 (p. 78),
Fan question: Who is the fastest crewmate when they run a 50-meter race?